Expression Profiling of Cadmium Response Genes in Ramie (Boehmeria nivea L.) Root

Abstract

Ramie (Boehmeria nivea), a perennial herb belongs to Urticaceae family, is a rapid growth and high biomass crop with highly tolerant and accumulative to heavy metals. However, the gene expression and regulation caused by cadmium (Cd) in ramie has not been well studied. In the present study, a gene expression database of ramie root in the absence (control) or presence of 100 μM Cd was established. Solexa high-throughput sequencing technology showed that 3,654,395 and 3,572,333 tags have been obtained from control and Cd treatment respectively. In total, 3887 genes were detected with significant differential expression levels, in which 2883 genes were up-regulated and 1004 genes were down-regulated. Gene ontology and pathway-based analyses were performed to determine and further to understand the biological functions of those differentially expressed genes. Fifteen genes were selected and their expression levels were confirmed by quantitative RT-PCR, and twelve of them showed consistent expression patterns with the digital gene expression data. Results on these expression profiling of genes lay the basis for biotechnological modification of new transgenic plants with improved phytoremediation capacity.

Analysis of BnMTL, a novel metallothionein‐like protein in the bast fiber crop Ramie (Boehmeria nivea)

“…Expression profiling of Cd 2+ response genes in root of ramie has been reported previously, with 36 unigenes from the cysteine and methionine metabolic pathway being up-regulated [11]. In the present study, the BnMTL gene cloned from ramie encodes a putative 46 amino acid protein with a molecular mass of 4.38 kDa.…”

“…Some wild genotypes were dominant in the smelter tailings, highlighting their hyperaccumulation properties. Ramie genome and genome‐wide expression profiles will aid the identification, quantification and annotation of key genes related to heavy metal tolerance. This will also be helpful for target discovery and pathway studies.…”

“…The phytoremediation technique for treating heavy metal contaminated soil includes phytoextraction, phytostabilization, rhizofiltration and phytovolatilization . Recent progress in phytoremediation aiming to curb heavy metal pollution has focused on the screening of suitable plant species that are potential heavy metal accumulators, such as Solanum nigrum , Helianthus annuus , Sorghum bicolor , Zea mays and Boehmeria nivea . Ramie ( Boehmeria nivea ) is conisidered to have excellent qualities for enduring heavy metal pollution and is considered as an ideal economic crop for the phytoremediation of mild or moderately heavy metal polluted areas as a result of several ramie varieties performing hyperaccumulative characteristics on heavy metals .…”

A MYB transcription factor, BnMYB2, cloned from ramie (Boehmeria nivea) is involved in cadmium tolerance and accumulation

“…Searching for novel genes involved in Cd tolerance and accumulation has become a priority in ramie breeding [45]. In our previous studies on the transcriptome profiling of cadmium response genes in ramie, unigene35788 was found to be significantly up-regulated in cadmium treated groups, which was annotated as MYB transcription factors using NR and KEGG database [40]. In the present study, a 1 733 bp full-length cDNA for this gene (named as BnMYB2) was isolated using 3'-RACE, 5'-RACE and RT-PCR methods.…”

“…In addition, it is a good candidate for phytoextraction of heavy metal polluted soils because its fiber is not in the food chain and is easy to harvest. In our previous studies on the transcriptome profiling of cadmium response genes in ramie, unigene35788 was found to be significantly up-regulated in cadmium treated groups, which was annotated as MYB transcription factors using NR and KEGG database [40].…”